Apparatus for preparing photocopies



,1965 w. LIMBERGER APPARATUS FOR PREPARING PHOTOCOPIES 1 m m w W k. M aM m U (I s R 2 m m Y B .0 g Km .0 vN MN 5* Mv m mm m Wm Wm M W mow m 9 l5 2 0 N w l n v dit AGENT Filed Nov. 25, 1958 2 Sheets-Sheet 2 l l v .7NVE N TOR. k/ALTEK L [HBEAGER United States Patent 3,16%,326 APPARATUSFOR PREPARING PHOTOCOPIES Walter Limberger, Hamburg, Germany, assignorto Lumoprint Zindler KG, Hamburg, Germany Filed Nov. 25, 1958, Ser. No.776,286 Claims priority, application Germany, Nov. 27, 1957, L 29,159;Dec. 20, 1957, L 29,329 16 Claims. (Cl. 95--75) The invention relates toan apparatus for preparing photocopies on sheet material by thedifiusion method with illuminating and developing devices in the samehousing, on one side of which parallel slots are arranged for theintroduction of copying paper and the original document.

The invention, in one advantageous embodiment, is based upon anapparatus with a known surface lamp. Such surface lamps have previouslybeen provided in combination with a developing device in the upper partof an apparatus with a cover covering the surface lamps, under which theillumination of the negative paper occurs. For introducing theilluminated negative paper together with the positive paper into thedeveloping device, the cover must first be opened and the negative paperplaced together with the positive paper and introduced through a specialslot into the developing device. The use of a surface lamp has theadvantage of a good illumination of the original, but also has thedisadvantage that copies cannot be prepared by a continuous method. Theusual arrangement of the surface lamps with an upwardly directed imagesupport leads to difiiculties in heat dissipation, since these imagesupports are continuously heated by upwardly rising air.

Furthermore, return travel of the original in known apparatus operatingwith a surface lamp to the discharge side of the apparatus requiresconsiderable space, so that the original is generally discharged at theopposite side of the apparatus. It is known to provide conveyingdevices, for example, which are guided round an illuminating deviceconstructed as a cylinder and the dimensions of the apparatus and itsconsumption are thereby considerably enlarged and the dissipation ofheat from the illuminating device is also rendered diflicult. Such a construction was not previously possible for apparatus in which copies areprepared on sheet material by the diffusion method and all copy papersand the original were inserted simultaneously, i.e. the positive andnegative papers with the original, when the negative paper lay directlyon the illuminating device and the original only lay behind the negativepaper.

Furthermore, there is the disadvantage in known apparatus that thepositive and negative papers discharged from the developing device stillcontain considerable moisture. These papers, which are dischargedadhering together from the developing device, must therefore be takenimmediately and either conveyed to a special drying apparatus orseparated so that drying can occur. Either a large consumption in viewof the use of additional devices arises or much space is required andthe drying lasts a considerable time.

The purpose of the invention is to avoid the disadvantages of knownconstructions.

This problem is solved in accordance with the invention in that on theimage support of the illuminating device provided with known surfacelamps one or more endless bands are arranged as conveying andcounter-pressure means for the original and negative paper and are eachguided around rollers arranged at each end of the image support, and thereturn run of the bands effects return movements of the original, whichis guided to this run through a separating device, in the vicinity ofthe intro- 3,168,026 Patented Feb. 2, 1965 "ice duction slots. With thisadvantageous construction, the paper can be introduced in the mannerdescribed above and the original can be conveyed to a discharge slot,which lies between the introduction slot for the original and thenegative paper and that for the positive paper.

A particularly advantageous construction is achieved by the elasticsuspension of the separating wall between the return movement channelfor the original and the introduction channel for the positive paper andthe resilient pressing of this wall against the conveying belt. In aparticularly simple manner, an apparatus construction requiring only asmall space is given, in which a through illumination can be carried outat a surface lamp and the original is discharged at the operating sidedirectly by its introduction slot.

In an embodiment of the device according to the invention, the originalmust be reversed by means of the separating device through a pathturning the original through about A pneumatic separating device isadvantageous for this purpose, with mutually opposite parallel suctionslots on each side of the original which are one behind the other in thedirection of advance and a nozzle, through which air is blown for thepurpose of separating the leading edges of the original and negativepaper. This nozzle extends preferably over the whole width of theoriginal and the negative paper.

According to a further embodiment of the invention, holding devices areprovided on one or more of the conveyer and pressure bands for theoriginal, in which the original is insertable and which automaticallyclose on passage of the original through the illuminating device andautomatically open in the region of the discharge slot for the original.By such holding devices, a satisfactory guiding of the original in theregion of the conveyer rollers arranged at the rear end of theilluminating support is ensured.

The holding means preferably consist of flaps which are connected withthe band at their ends lying in the direction ofadvance. At the curvedpath of the one or more bands lying at the end of the illuminatingdevice, a guiding member pressing the flaps on the band or bands isprovided, so that the flaps serving as the holding device remain closedon curved guiding of the bands at the supporting rollers. This guidingextends in conformity with the curvature of the one or more bands fromthe illumination support of the illuminating device to the inlet of thereturn guiding channel for the original, in which the flaps are heldclosed by contact of the band against the guiding wall.

The guiding member is advantageously provided with a sharply pointedclaw member facing opposite to the direction of advance, at which thenegative paper is raised from the original.

The flaps are advantageously made integral with the conveyor belts orbands and are formed by slits made at an incline thereinto. According toanother embodiment, the flaps consist of scoop-like plates arranged onone or more of the conveyor band-s which are made of synthetic material,for example nylon, and are advantageously transparent and, despite theirelasticity, have a certain stiffness, which ensures their opening onrelease from the guide means. The transparent construction of the smallplates ensures that the edge parts in pictures beneath the plates arecopied.

Furthermore, a separator is arranged at the reversal point of the one ormore conveying bands at the beginning of the illuminating device, whichalso includes a guiding surface from which the original is guided intoits discharge slot. The separator is provided with guiding projectionswhich engage between separate conveying bands or in longitudinal groovesin the conveying bands and release the forward edge of the original fromthe holding means, which open at this point, for example, due to thewidth of the guide channel.

According to an especially preferred embodiment, the invention providesthe arrangement of the illuminating device with a known surface lampunder the ventilation openings provided in the substantially horizontalupper wall of the housing and a downwardly directed illuminationsupport, wherein at the discharge slot of the develop ing device, whichlies at the opposite side of the apparatus with respect to the sideincluding the introduction slots, reversal means are provided whichguide the copy paper in the direction toward the operating side of theapparatus and dispose it on a drying device. This construction has theadvantage that operation of the device from the one side is possible.The operation is thus considerably simplified and the rapidity in themanufacture of copies is considerably increased.

The drying device for the copy papers discharged from the illuminatingdevice is supplied with heat from the known illuminating device. Such adrying device in the manufacture of sheet material permits in a novelmanner the utilization of the heat evolved in the illumination andprovides the possibility that the copy paper need only be held andfurther treated after drying. A considerably more ready handling withrespect to known apparatus is thus ensured.

Further advantages and features of the invention will appear from thefollowing description of a constructional embodiment illustrated in thedrawing. In the drawings:

FIG. 1 shows a longitudinal section through an apparatus, in which onlythe main parts are illustrated;

FIG. 2 shows a part view of the apparatus according to FIG. 1 fromabove;

FIG. 3 shows a section of the apparatus according to FIG. 1, forillustrating a preferred construction of the separating device;

FIG. 4 shows a side view in section of the essential parts of the devicewith an illuminating device and a developing device;

FIG. 5 shows a perspective view of the separator used in FIG. 4;

FIG. 6 shows an enlarged section of FIG. 4 for illustrating theseparation of the original and the negative paper;

FIG. 7 shows a perspective part view of the part of the apparatusaccording to FIG. 4, for illustrating the separation of the original andthe negative paper;

FIG. 8 shows a diagrammatic representation of the driving means for thedevice shown in FIG. 4.

All the apparatus is enclosed in a flat housing 1, along one side ofwhich three parallel slots 2, 3 and 4 are arranged directly together.The outer slots 2 and 4 are provided with outwardly diverging inlets andare constructed as inlet slots. The original and the negative paper areinserted into the slot 2, whereas the positive paper is inserted intothe slot 4. The original is discharged from the slot 3 afterillumination. The slot 3 is made small. Its limiting walls 5 and 6converge to reduce the outlet of the slot 3 conically, whereby theaccidental insertion of a paper into the slot 3 is prevented, since inthe selected form the paper to be inserted is diverted into the slots 2and 4.

The simultaneous introduction of all papers and the original necessaryfor the preparation of copies has the advantage of a saving of time inthe manufacture of copies and also the avoidance of intermediateilluminations, if as is necessary in known apparatus, the negative papercan only be brought into contact with the positive paper and insertedinto the cover after the illumination.

In the upper part of the housing 1, the illuminating device 7 isarranged so that the illumination support 8, consisting for example of aglass plate, lies beneath the illuminating lamps 9 of the illuminatingdevice. The

illumination is hence effected in the direction towards the base of thehousing 1.

The chamber containing the illuminating device 7 is extended by anintermediate wall 11 extending above the developing device 10, under theupper wall 12 of the housing, to the discharge slot 13 of the developingdevice 18. The chamber containing the illuminating device 7 henceextends to the upper wall 12 over. a region which corresponds to theshape of the sheet material with which the copies are prepared. in thisregion, the upper wall 12 is provided with ventilation openings 14through which the heat evolved in the illuminating device 7 passesupwardly from the apparatus or is blown out in this direction by aventilator fan.

The insertion slot 2 for the original and the negative paper leads tothe illumination support 8, under which the conveying device for theoriginal and the negative paper is located. This conveying deviceconsists of a conveyor belt-like apparatus. In the embodimentillustrated, a guide or driving roller 15 or 16 is provided at the endof the illumination support 8, over which several endless textile bands17 are stretched in side-by-side relation. The use of several bandsarranged side-by-side ensures uniform contact over the whole width ofthe illumination support. The uniform contact in the longitudinaldirection of the illumination support 8 is improved, since the glassplate forming the illumination support 8 is convexly curved in thedirection of the conveying bands 17 in a plane parallel andperpendicular to the advance. The conveying bands 17, which merely guidefrom the start to the end of the illumination support 8, adaptthemselves to the shape of the illumination support 8 in this way. Inorder to improve the contact even further, in an advantageousembodiment, the driving rollers 15, 16 are guided in slots parallel tothe surface of the illumination support 8 and are resiliently pressedtogether. In the embodiment illustrated, the arrangement is such thatparticularly the end part of the developing device 16 facing theillumination support 8 rises, so that the intermediate wall 11 can beconstructed as an extension of the illumination support 8. By this,advantageous flow properties are given for the exit of the heated airvia the ventilation openings 14, which lie in the vicinity of thedischarge slot 13 of the developing device 10.

A separating wall 18 is resiliently suspended between the conveyingbands 17. This separating wall lies between the channel to the returnconveyor for the original to the discharge slot 3 and the insertingchannel behind the insert slot 4 for the positive paper. The separatingwall 18 is rigidly suspended at the points 19 and 20 for example. At thelatter point, it passes into the limiting wall 5 for the slot 3, whereasin the first-mentioned point it passes into a separating wall 21 betweenthe guide members 22 and 23 through the developer bath 24. Theseparating wall 18 is resiliently urged against the return run of theconveying belt 17. Since the separating wall 18 is constructed with avery smooth surface, the conveyance of the original to the dischargeslot 3 is thus ensured.

The pressure on the separating wall 18 is effected in the embodimentillustrated by the conveying rollers 25 and 26 for the positive paper.These conveying rollers 25 and 26 run with the same direction ofrotation as the driving rollers 15, 16 for the conveyor belt 17. Therollers 25 and 26, which are arranged substantially perpendicularlybeneath the driving rollers 15 and 16, are advantageously drivinglycoupled by a simple belt drive, which is indicated at 27 and 28. Theaxes of the rollers 25 and 26 are guided in substantially perpendicularslots, for example in the side walls. By the use of elastic belts 27 and29, for example of rubber, the rollers 25 and 26 are drawn upwardly,whereby at the same time the separating wall 18 is urged against thereturn run of the conveyor belt 17. The lower limiting wall of thechannel for the positive paper is formed by a rigid intermediate wall29.

By the conveying arrangements according to: the invention, aconstruction effecting the pressing of the original and the negativepaper against the illumination support 8 and, at the same time, thereturn movement of the original is provided, which requires extremelylittle space and, in the use of a surface lamp for illuminating by thethrough method, effects a return of the original in the vicinity of theinlet slot, although the transport device merely being arranged beforethe illuminating support 8 of the illumination device, i.e., is notguided round the illuminating device, and wherein the positive paper isinserted into the device at the same time as the original and thenegative paper.

Behind the illumination support 8, a separating device for separatingthe original from the negative paper is arranged. This separating deviceis constructed as a pneumatic device in the embodiment illustrated.Within the scope of the invention, other constructional forms of suchseparating devices are included.

The separating device shown includes a suction box 30 behind theillumination support 8 and a further suction box 31 behind the upper runof the conveyor belt 17, in which a subpressure can be produced by theventilator fan of the apparatus. These suction boxes, because of theirdivergent arrangement in the direction of advance in connection with aseparating surface 32, leads to separation of the original from thenegative paper, which continues in the path 22 to the developing device10.

A dilferent and preferred construction form of the separating device isillustrated in an enlarged scale in FIG. 3. In this figure, the sameparts are provided with the same references as in FIG. 1. In thisconstruction, two suction boxes are provided one behind the other, whichhave at the facing sides several parallel slots 44, 45 extendingside-oy-side and in the direction of advance. Between the suction boxesprovided with the slots 44 and 45, a nozzle 46, projects from the sideof the developing device 1t), through which air is blown on to theleading edges of the original and the negative paper emerging from theillumination support 8 in order to effect a separation of the papers.The combined effect of the suction slots 44, 45 and the air jet from thenozzle 46 ensures a satisfactory separation at the most rapid rate ofadvance.

The nozzle 46 is supplied with air through a channel 47. The nozzle 46preferably has the same width as the original or the negative paper.

Behind the guide or path members 22 and 23 of the developing device 10,a pair of pressure rollers 33, 34 is arranged, which on the one handpress out the moisture adhering to the papers and on the other handcause their discharge through the slot 13. A pair of pressure rollerscan be constructed in the usual way with elastic roller surfaces or withotherwise compressible rollers.

At the discharge slot 13, reversing means 35 are ar ranged. Thesereversing means consist in the embodiment illustrated of a curvedguiding surface which can have the shape of a section of a cylindricalsurface. The curvature is selected so that the paper emerging throughthe slot 13 is guided toward the region of the upper wall 12 of thehousing 1, which is provided with ventilation openings 14 and whichforms the drying device 43. The papers are thus directed toward thefront side including the slots 2, 3 and 4, so that they can be readilyremoved from the operating side of the apparatus after drying by meansof the air passing through the ventilating slots 14.

Beneath the intermediate wall 29, a space is located with the drivingand connecting parts for the apparatus. For example, a driving motor 36is provided which drives all the moving parts. These includeparticularly the driving rollers 15 and 16 and the pair of conveyingrollers 33, 34, as well as the ventilator fan which is indicated at 37.The ventilator fan produces on the one hand the subpressure in thesuction boxes 30, 31 and, at the same time, the stream of air throughthe nozzle 46 and also a ventilating air stream through the illuminatingdevice 7, so that on cooling of the illumination support 8 the heatedair is discharged upwardly through the ventilating openings 14 accordingto the arrow 38. The air coming from the ventilator fan can be guidedlaterally of the illuminating device 8 for example. According to anotherembodiment, the ventilator fan is arranged in the space 38, so that itblows on to the illumination support 8, whereby an air stream is set upwhich is distributed by baffle means and vortex formation to all theventilation openings 14.

Beneath the intermediate wall 29, additional electric switching andconnection means 96 are provided.

In operation, the original and the negative paper are introduced throughthe slot 32, the negative paper being disposed with the downwardlyfacing layer uppermost and the original with the upwardly facing pictureor image downwards. The positive paper is inserted into the slot 4,together with these papers.

The original and the negative paper are separated, after moving towardsthe illuminating device 7, in the separating device 30 and 31, whereinthe original is guided at the separating wall 32 corresponding to thearrow 40 toward the lower run of the conveyer belt 17 and is returned tothe discharge slot 3 between the conveyer belts and intermediate wall18. Teh illuminated negative paper passes corresponding to the arrow 41into the path 22 of the developing device i At the same time, thepositive paper passes into the path 23 of the developer device. Withuniform driving of the driving rollers 15, 16 and the conveying rollers25, 26, the diameters of the rollers are so chosen that the positivepaper runs into the bath 24 simultaneously with the negative.

After leaving the bath 24, the positive and negative papers aredischarged from the pair of rollers 23, 24 in the direction of the arrow42 through the slot 13 and are guided by means of the guide surface 35over the ventilation openings 14, where a predrying of the papersoccurs.

The surface of the upper wall 12 of the housing 1 delineated by theventilation openings 14 forms the drying region 43, whose limits areshown in FIG. 2 by a dotted line.

FIG. 4 shows an overall view of the device according to the invention,wherein only the parts of an apparatus essential for the invention areillustrated. The apparatus is shown completely in FIG. 1.

The apparatus includes an illuminating device, of which two lightsources 48 and 49 and an illumination support 50 curved concavely to thelight sources are shown. The apparatus further contains a developingdevice, which consists of a bath 51, through which the positive paper isguided in a guiding path 52 and the illuminated negative paper in aguiding path 53. Behind the bath 51, a pair of drying and conveyingrollers are located (not shown in the drawing), through which thenegative and positive papers are discharged from the apparatus.

Slots are arranged in the side wall of the apparatus on the left asshown (which are not illustrated in detail in the drawings.) Theuppermost slot 54 serves for introducing the negative with its layerdownward. Through the slot 55, the original is inserted with the imageupwards and the negative, with the layer facing upwards, is insertedthrough the slot 56. The discharge slot 57 for the original is arrangedbetween the slots 55 and 56. This slot narrows towards its outlet, sothat accidental insertion of the paper into this slot is prevented.

The slot 54 is covered by a transparent guide wall 58, in anadvantageous construction, which extends to the illumination support 50of the illuminating device. The guide path for the negative paper isseparated from that of the original by a further guide plate 59. Thisguide plate is also transparent, so that the guide path for the originalcan be seen from above. There is also a construction in which the guideplates 58 and 59 are provided with openings, which permit control of theinsertion of the original. The guide plate 59 extends with its endsfacing the illuminating device to the vicinity of the illuminationsupport 50 of the illuminating device. The spacing is so dimensionedwith reference to the holding means constructed as flaps and describedin greater detail below that these flaps cannot separate in the guidepath of the negative paper.

Beneath the illumination support 50, a conveying and pressure device isprovided consisting of a wide band or several smaller bands 60. Thebands 60 are guided and driven by conveying rollers 61 and 62 arrangedat each end of the illuminating device. By the curvature of theillumination support 50, a suificiently strong pressing of the originalagainst the negative paper and of both papers against the illuminatingdevice is ensured, without supporting the bands 60 between the rollers61 and 62.

The return run of the bands 6t) extends along the preferably elasticallyarranged side wall 63, which at the same time is a limiting wall for thereturn guide path 64 of the original and at one side limits thedischarge slot for the original. -The guide wall 63 is advantageouslymade curved. The guide wall is preferably curved upwardly, so that thepressure between the conveyer bands 16 and the guide wall 63 between theguiding rollers 61 and 62 is ensured without special supporting means.Beneath the guide wall 63, a further guide path 65 is located, whichterminates on the one hand in the slot 56 and on the other hand in theguide path 52 through the bath 51. The elastically suspended guide Wall63 is carried at least in the region of the return run of the band 60upon rollers 66, 67, which have an elastic surface or are yieldinglymounted in the vertical direction. These rollers 66, 67 serve to conveythe positive paper to the lower side of the guide wall 63 and at thesame time to press the guide wall against the return run of the bands60.

In the embodiment shown, flaps are arranged in the band indicated inFIG. 4 at 60, as the holding means. These flaps are formed in thisembodiment by slits in the surface of the band which are downwardlyinclined in the direction of advance. One such flap is indicated at 68.

The band 69 is preferably a rubber belt with a fabric surface. Aconstruction of rubber and also the stiffened fabric covering ensurethat the flap 68 is spread open because of its elasticity on curving ofthe band 60, even if no special guide means are provided. Such an openposition is shown at 68. It may be mentioned that the guide plate 59 ismade so wide at the illumination support that the flap 68 cannot open inthe guide path for the negative paper because of the curvature 61 at theleading end of the illumination support 50. The rounding off '69 servesfor guiding the negative paper between the illumination support 50 andthe band 60.

On passage of the band, for example, due to driving of the roller 61 inthe direction of the arrow indicated, the band 60 runs under pressurealong the illumination support 50. The flap 68 is thus pressed againstthe underside of the band over its whole length.

In the curved section at the return point of the band 60 at the roller62, a claw section member 70 is provided as a guide which is sharplypointed at the end 71 facing the illumination support 50. This guidemember 70 or its forward end 71 lies on the conveyer band 60 andprevents the flap 68 opening as a result of curvature of the band. Anoriginal held in the flap 68 is thus drawn with the band 60 round theroller 62, whereas a negative paper arranged on the original is raisedupon the end 71 of the member 70 and guided into the guide path 53. Thispart of the process is illustrated on an enlarged scale and inperspective in FIGS. 6 and 7. The same parts are provided with the samereferences in this embodiment.

As shown in FIG. 6, the end 71 of the guide member 76 is pressed with acertain pressure against the band 60, which can be somewhat compressedin its thickness at this position. This pressure is provided merely inthe region of the end 71 at which occurs the separation of the original72 from the negative paper 73. In special constructions, such acompression is not necessary. It is to be noted, that the original,which projects into the band 60, cannot release its securement to thisband and is consequently drawn along with the band 60. The negativepaper 73 passes straight on and, particularly with a certain compressionof the band by the forward end 71 of the guide member 70, passes to theupper side of the member and is consequently moved because of theadvance into the guide path 53.

The same process is illustrated in FIG. 7. In PEG. 7, the band indicatedat 69 merely has a relatively narrow width and is arranged in the middleof the guide path. Laterally of the band 60, further bands 74, 75 arearranged. It should be expressly noted that, although only two furtherbands are shown in the drawing, several bands are advantageouslyarranged side-by-side. In the embodiment illustrated in FIG. 7, theillumination support is sharply curved upwardly at its end facing thedeveloping device, whereby the negative paper, on leaving the gapbetween the conveying belts and the illumination support, is raised fromthe original and runs to the rear of the guide member 70.

The original is carried by the band 65 to the guide Wall 63 in the guidepath 64. The upper limiting wall of the return guide path 64 is formedby a separator 76, one end of which divides the slots and 57 from oneanother. The end facing the band 60 includes a widened section, which isconcave corresponding to the curvature of the roller 60. At the loweredge of the separator 76 facing the band, separating projections 77 arearranged, which can be seen best in Fiji. 5. These projections 77, in anembodiment according-to FIG. 7, engage for instance in intermediatespaces between the bands '74, 60 and or, in using a wide band, inlongitudinal grooves in such band. The separating projections 77 are soconstructed and of such length that they extend deeper than the flaps68, i.e. the forward ends of the separating projection 77 are locatednearer to the roller 61 than the deepest parts of the slits in the bandbeneath the flaps 68. On passage of the band, the separator projections77 hence engage beneath the forward edge of the original and guide thisto the discharge slot 57. It may be mentioned that the guide path 64beneath the separating projections 77 is made of such a width that theflaps 68 can open freely, so that the original can pass out under theseflaps. It is also to be noted that the flaps 68 are illustrated on anenlarged scale to facilitate the disclosure. The spacing of the concavesurface 7 8 of the separator 76 from the band 60 is so large thatmovement of the band with the flap 68 open is possible at least at thelower edges carrying the middle projection 77.

In the use of the device described, various constructional forms areprovided. One embodiment includes directly successive flaps 68 in one ormore bands, wherein these flaps can partly overlap one another inscoop-fashion. This construction of the apparatus is particularlysuitable for continuous operation, since the original is introduced withthe band moving and is then gripped by the flap located at the start ofthe illuminating support and is held therein. According to anotherembodiment, a few flaps are arranged at a certain distance apart. Inthis embodiment, a stepwise operation of the process takes place, theconveyer band being driven until the original lies along the lower runof the conveyor band. In this position, an unused flap is located in theposition of the flap indicated in FIG. 4 at 68, so that, on arrest ofthe band and while observing through the transparent conductor walls 58and 59, a new original together with new papers can be inserted. In thefurther operating step, the first original is discharged from thedischarge slot 57, whilst the subseguently introduced original is guidedalong the guide wall An example of the construction of such a drive isillustrated in FIG. 8. This is fundamentally a drive in accordance WithGerman Patent 923,112. The driving motor 79 operates on the one hand byway of a chain drive 80 to control the moving parts of the apparatus,for example, the conveyer roller 61. On the other hand, via a chaindrive 8-1, an appropriate gear reduction mechanism 83 is driven and fromthis a control cam 84 is driven via a driving belt 82. The belt has theadvantage that, because of the overrun of the electric motor onde-energising and the instantaneous arrest of the control cam 84, itbecomes stressed in the operation described subsequently. This tensionremains after arrest of all parts, so that the control cam 84 is movedmomentarily into a following position because of the tension stored inthe belt, so that movement of this cam disc by the cam 86 mentioned inthe following and the aperture 85 is prevented directly afterenergisation, even if actuation is only extremely short.

The drive 83 is provided with a ratchet wheel 94, on which a pawl 95engages. This arrangement can be replaced by some other one-waycoupling. The purpose of this arrangement is to prevent return rotationof the driving motor 79 by detensioning of the belt 82 on arrest of thedevice.

This control cam 84 is provided with an aperture 85, into which a cam 86is drawn by means of a spring 87. The cam 86 is located upon a pivotlever 88 on which the spring 87 engages. The pivot lever 88 is alsoconnected to an actuating device 89, by which it can be pivoted. Forexample, this could be the operating knob of the apparatus. The pivotlever 88 serves to actuate a switch with the contacts 90, 91 in thecircuit 92 of the driving motor 79. The lever 88 operates on the contact91 by way of a spring leaf 93.

If the actuating knob 89 is pressed, the cam 86 is lifted out of theaperture 85 and the switch 90, 91 is closed. The motor 79 rotates and atthe same time drives the control cam 84. On release of the actuatingknob 8-9, the cam slides on the surface of the disc 34 until, after arevolution of the control cam, it is drawn into the aperture 85 by thespring 87. At the same time, the switch 9t), 91 is opened so that themotor comes to rest.

What I claim is:

l. A photocopying device for reproducing a master copy on sheetmaterial, comprising a housing having a base, walls connected to saidbase and a cover plate connected to said walls, one of said walls beingprovided with at least one slot adapted to admit a first sheet carryingthe master copy and a second sheet having a photosensitive surfaceadapted to receive an image of said master copy, said housing furtherhaving an exit slot for said first sheet adjacent said one slot;illuminating means within said housing comrising a light-transmissivefirst guide plate and a light source disposed on one side of said guideplate; conveyor means within said housing disposed on the other side ofsaid guide plate, said conveyor means comprising an endless band, atleast two axially spaced support rollers for said band and drive meansfor said support rollers, said band having a forward run and a returnrun, said forward run being positioned and adapted to press said sheetsagainst said guide plate with said first sheet lying next to said band;a developing section positioned beyond said conveyor means within saidhousing; sheet-separating means between said conveyor means and saiddeveloping section; and guide means for said sheets adjacent saidconveyor means; said sheet-separating means being positioned and adaptedto deflect said second sheet from said band into said developing sectionwhile directing said first sheet between said return run and said guidemeans; said guide means comprising a second guide plate resilientlybearing on said return run and extending toward said exit slot.

2. A photocopying device according to claim 1 wherein said second guideplate terminates in said exit slot and forms a separate opening thereinfor the entrance of a third sheet, further comprising transport meansadapted to direct said third sheet into said developing section; saiddeveloping section comprising a developer container, a pair of squeezerollers beyond said container and guide elements adapted to pass saidsecond and third sheets into said container and thence between saidsqueeze rollers, thereby transferring said image from said second sheetonto said third sheet.

3. A photocopying device according to claim 2 wherein said housing isprovided with a pair of opposite wall slots extending substantiallyperpendicularly to said band, said transport means comprising at leastone further roller bearing on said second guide plate, said furtherroller being displaceably journaled in said wall slots, and spring meansurging said further roller against said second guide plate.

4. A photocopying device according to claim 2 wherein said forward runlies above said return run, said cover plate defining with said firstguide plate a compartment containing said light source, said cover platehaving airexhaust apertures above said compartment and, beyond saidapertures, a discharge slot for said third sheet, said first guide plateextending to said cover plate between said apertures and said dischargeslot.

5. A photocopying device according to claim 1 wherein saidsheet-separating means includes a pneumatic device comprising first andsecond suction means facing each other at a location beyond said forwardrun for co-operation with said first and second sheets, respectively.

6. A photocopying device according to claim 5 wherein said pneumaticdevice further comprises air-discharge means positioned beyond saidfirst and second suction means and adapted to blow a stream of air ontothe oncoming leading edges of said sheets.

7. A photocopying device according to claim 6 where in saidair-discharge means comprises a nozzle of substantially the same widthas said sheets whereby said stream of air contacts said leading edgesalong the entire length thereof.

8. A photocopying device according to claim l, comprising partitionmeans at said one wall, said one wall being provided with another slotseparated from said one slot by said partition means and adapted toadmit said second sheet concurrently with the admission of said firstsheet through said one slot, said band being provided withsheet-gripping means passing through a position of alignment with saidpartition means on said forward run, said partition means upon suchalignment directing said first sheet into engagement by saidsheetgripping means while deflecting said second sheet past saidsheet-gripping means onto said forward run.

9. A photocopying device according to claim 8 wherein saidsheet-gripping means comprises at least one rearwardly pointing flapextending integrally from the outer surface of said band.

10. A photocopying device according to claim 8 wherein said one wall hasa portion extending generally parallel to said partition means intosubstantial alignment with said first guide plate and defining saidother slot with said partition means, said portion and said partitionmeans being transparent for enabling observation of said sheets fromwithout.

11. In a photocopying device for transferring an image from a firstsheet onto a second sheet, in combination, a housing formed with anentrance for said sheets, a first roller in said housing adjacent saidentrance, a second roller in said housing remote from said entrance,endless beit means embracing said rollers, said belt means having aforward run extending from said first roller to said second roller and areturn run extending from said second roller to said first roller, afirst pressure plate adjacent said forward run adapted to maintain saidsheets, upon their simultaneous introduction through said entrance, inface-to-face relationship with each other and in close contact with saidband whereby said sheets are conveyed toward said second roller,sheet-separating means at said second roller for directing the outer oneof said sheets away from said band, guide means extending around saidsecond roller and forming a path terminating at said sheet-separatingmeans for directing the inner one of said sheets onto said return run, asecond pressure plate at said return run adapted to maintain said innersheet in close contact with said band for entrainment of said innersheet toward said first roller, discharge means for said inner sheet atsaid first roller, and partition means at said entrance forming a firstchannel for said outer sheet and a second channel for said inner sheet,said first channel terminating at said first pressure plate outside thesurface of said belt means, said belt means being provided with aflexible, rearwardly pointing surface formation defining a wedge-shapedrecess aligned with said second channel upon passing around said firstroller whereby the leading edge of said inner sheet can be introducedinto said recess while said outer sheet is deflected past said surfaceformation onto said forward run; said sheet-separating means comprisingblower means in the region of said second roller adapted to direct astream of air onto the oncoming leading edges of said sheets.

12. The combination according to claim 11 wherein said sheet-separatingmeans further comprises first and second suction means facing each otherbetween said forward run and said guide means.

13. The combination according to claim 11 wherein said guide means formsan integral extension of said second pressure plate.

14. The combination according to claim 11 wherein said first pressureplate is transparent, further comprising a light source in said housingadjacent said first pressure plate for illuminating said sheetstherethrough.

15. The combination according to claim 14 wherein said rollers havesubstantially horizontal axes, said first pressure plate and said lightsource being positioned above the upper run of said belt means.

16. In a photocopying device for transferring an image from a firstsheet onto a second sheet, in combination, a housing formed with anentrance for said sheets, a first roller in said housing remote fromsaid entrance, a second roller in said housing remote from saidentrance, endless belt means embracing said rollers, said belt meanshaving a forward run extending from said first ,roller to said secondroller and return run extending from said second roller to said firstroller, a first pressure plate adjacent said forward run adapted tomaintain said sheets, upon their simultaneous introduction through saidentrance, in face-to-face relationship with each other and in closecontact with said band whereby said sheets are conveyed toward saidsecond roller, sheet-separating means at said second roller fordirecting the outer one of said sheets away from said band, guide meansextending around said second roller and forming a path terminating atsaid sheet-separating means for directing the inner one of said sheetsonto said return run, a second pressure plate at said return run adaptedto maintain said inner sheet in close contact with said band forentrainment of said inner sheet toward said first roller, dischargemeans for said inner sheet at said first roller, said discharge meanscomprising stripper means provided with at least one tongue engagingsaid belt means in the region of said first roller at a location oifsetfrom the path of said surface formation, and partition means at saidentrance forming a first channel for said outer sheet and a secondchannel for said inner sheet, said first channel terminating at saidfirst pressure plate outside the surface of said belt means, said beltmeans comprising a plurality of endless, parallel portions transverselyseparated at least on their surface, said belt means further beingprovided with a flexible, rearwardly pointing surface formation defininga wedge-shaped recess aligned with said second channel upon passingaround said first roller whereby the leading edge of said inner sheetcan be introduced into said recess while said outer sheet is deflectedpast said surface formation onto said forward run, said tongue enteringthe separation between said portions to a depth greater than that ofsaid recess, said sheet-separating means comprising a rearwardlypointing wedge-shaped formation bearing upon said belt means in theregion of said second roller in alignment with said surface formationwhereby the latter is urged into firm contact with said inner sheetwhile said outer sheet is deflected from said belt means, said secondpressure plate being provided with an extension forming with saidstripper means a third channel for the removal of said inner sheet fromsaid belt means, said third channel being wide enough adjacent said beltmeans for enabling an erection of said surface formation sufiicient torelease said inner sheet.

References Cited by the Examiner UNITED STATES PATENTS 2,194,808 3/40Pooley 8824 2,317,343 4/43 Betts -75 2,402,929 6/46 Sutherland 95-752,431,520 11/47 Streich 9577.5 2,478,850 8/49 Trump 27163 2,574,21511/51 Kunstadter 9577.5 2,606,478 8/52 Pratt 8824 2,732,778 1/56Limberger 9577.5 2,878,742 3/59 Trump 9577.5

NORTON ANSHER, Primary Examiner.

D. B. LOWE, E. E. FULLER, ROBERT L. EVANS,

Examiners.

1. A PHOTOCOPYING DEVICE FOR REPRODUCING A MASTER COPY ON SHEETMATERIAL, COMPRISING A HOUSING HAVING A BASE, WALLS CONNECTED TO SAIDBASE AND A COVER PLATE CONNECTED TO SAID WALLS, ONE OF SAID WALLS BEINGPROVIDED WITH AT LEAST ONE SLOT ADAPTED TO ADMIT A FIRST SHEET CARRYINGTHE MASTER COPY AND A SECOND SHEET HAVING A PHOTOSENSITIVE SURFACEADAPTED TO RECEIVE AN IMAGE OF SAID MASTER COPY, SAID HOUSING FURTHERHAVING AN EXIT SLOT FOR SAID FIRST SHEET ADJACENT SAID ONE SLOT;ILLUMINATING MEANS WITHIN SAID HOUSING COMRISING A LIGHT-TRANSMISSIVEFIRST GUIDE PLATE AND A LIGHT SOURCE DISPOSED ON ONE SIDE OF SAID GUIDEPLATE; CONVEYOR MEANS WITHIN SAID HOUSING DISPOSED ON THE OTHER SIDE OFSAID GUIDE PLATE, SAID CONVEYOR MEANS COMPRISING AN ENDLESS BAND, ATLEAST TWO AXIALLY SPACED SUPPORT ROLLERS FOR SAID BAND AND DRIVE MEANSFOR SAID SUPPORT ROLLERS, SAID BAND HAVING A FORWARD RUN AND A RETURNRUN, SAID FORWARD RUN BEING POSITIONED AND ADAPTED TO PRESS SAID SHEETSAGAINST SAID GUIDE PLATE WITH SAID FIRST SHEET LYING NEXT TO SAID BAND;A DEVELOPING SECTION POSITIONED BEYOND SAID CONVEYOR MEANS WITHIN SAIDHOLUSING; SHEET-SEPARATING MEANS BETWEEN SAID CONVEYOR MEANS AND SAIDDEVELOPING SECTION; AND GUIDE MEANS FOR SAID SHEETS ADJACENT SAIDCONVEYOR MEANS; SAID SHEET-SEPARATING MEANS BEING POSITIONED AND ADAPTEDTO DEFLECT SAID SECOND SHEET FROM SAID BAND INTO SAID DEVELOPING SECTIONWHILE DIRECTING SAID FIRST SHEET BETWEEN SAID RETURN RUN AND SAID GUIDEMEANS; SAID GUIDE MEANS COMPRISING A SECOND GUIDE PLATE RESILIENTLYBEARING ON SAID RETURN RUN AND EXTENDING TOWARD SIA EXIT SLOT.